Low Parts Per Trillion
Detection of Iodinated Disinfection
Byproducts in Drinking Water and Urine using Vacuum-Assisted Sorbent
Extraction and GC–MS/MS
posted on 2023-12-30, 14:07authored byPatrick T. Justen, Madison L. Kilpatrick, Joshua L. Soto, Susan D. Richardson
Disinfection byproducts (DBPs) are ubiquitous environmental
contaminants,
which are present in virtually all drinking water and linked to detrimental
health effects. Iodinated-DBPs are more cytotoxic and genotoxic than
chloro- and bromo-DBPs and are formed during disinfection of iodide-containing
source water. Liquid–liquid extraction (LLE) paired with gas
chromatography (GC)–mass spectrometry (MS) has been the method
of choice in the study of low molecular weight iodinated-DBPs; however,
this method is laborious and time-consuming and struggles with complex
matrices. We developed an environmentally friendly method utilizing
headspace solid phase extraction with the application of vacuum to
measure six iodinated-trihalomethanes (I-THMs) in drinking water and
urine. Vacuum-assisted sorbent extraction (VASE) has the ability to
exhaustively and rapidly extract volatile and semivolatile compounds
from liquid matrices without the use of solvent. Using VASE with GC–MS/MS
provides improved analyte recovery and reduced matrix interference
compared to LLE. Additionally, VASE enables extraction of 30 samples
simultaneously with minimal sample handling and improved method reproducibility.
Using VASE with GC–MS/MS, we achieved quantification limits
of 3–4 ng/L. This technique was demonstrated on drinking water
from four cities, where five I-THMs were quantified at levels 10–33
times below comparable LLE methods with 10 times lower volumes of
sample (10 mL vs 100 mL).